GMSCAL

VIS data is 6-bit. Calibration is achieved with a 64-value VIS level-albedo lookup table. This calibration table is interpolated to make a 256-value table. IR data is 8-bit. Calibration is achieved with a 256-value IR level- temperature lookup table, which may change with the spacecraft.

The GMS calibration file is supplied with McIDAS-X.

Word allocation

Word

Description

0

number of IR calibration tables in the file

1

identification number of the first IR table in the file

2

identification number of the second IR table in the file

511

identification number of the 511th IR table, if present

512-767

interpolated VIS calibration table; albedos are multiplied by 10**6 and stored as integers

1024-1279

first IR calibration table in the file; it corresponds to the identifier stored in word 1; temperatures are multiplied by 10**3 and stored as integers

1280-1535

second IR calibration table in the file; it corresponds to the identifier stored in word 2 and is only present if the calibration table changes with the spacecraft